Nicholas BertinelliCold Fusion
What is Cold Fusion? "Cold fusion describes a form of energy generated when hydrogeninteracts with various metals like nickel and palladium" (
http://coldfusionnow.org/what-is-cold-fusion/).

When Hydrogen is introduced to certain metals, like Nickel and Palladium, then a chemical reaction occurs which produces heat, which can be used to make energy. Please keep in mind that these are all hypothetical and Cold Fusion is still on its way to becoming a reality.
external image Cold_fusion_electrolysis.svg
Cold Fusion is called Low-Energy Nuclear, or LENR. LENR produces a very clean source of energy that creates heat to make hot water. This is what separates this sort of fusion from all of the other kinds of nuclear fusion.
Cold Fusion, in theory, will be able to provide us with a large amount of cheap energy. If it does end up becoming a reality then there will be millions of cold fusion generators around the world, from small personal devices to large gigawatt generators!
250px-Cold-fusion-calorimeter-nhe-diagram.png
The problem with cold fusion, as stated by NASA, is because "
NASA says that the 5-30THz frequency required to oscillate the nickel lattice is hard to efficiently produce" (
http://www.extremetech.com/extreme/149090-nasas-cold-fusion-tech-could-put-a-nuclear-reactor-in-every-home-car-and-plane).
NASA has been testing with cold fusion in order to see if it can be used efficiently; it is still years away from being used in the way they want it to be used, which is having a cold fusion reactor in every car, plane, and house.